1. Field of the Invention
The present invention generally relates to chip mounters. More particularly, the present invention relates to a component recognition apparatus for a chip mounter.
2. Description of the Related Art
Chip mounters are used to mount components such as integrated circuit (IC) components, semiconductor packages, etc. on a substrate such as a printed circuit board (PCB). Recently, both PCBs and individual IC components have become complex and highly integrated. Accordingly, IC components mounted on PCBs have a large number of very closely spaced output pins.
Before an electronic component is mounted on a PCB it is picked up by a chip mounter and held by suction on a nozzle. To ensure accurate placement of the component on the PCB and proper alignment of connectors of the electronic component with traces of the PCB, the nozzle of the component mounter may rotate the component by an angle. To facilitate determination of the component angle, a component recognition apparatus is provided.
The component recognition apparatus is generally attached to the main body or the head of a chip mounter. In a conventional component recognition apparatus that is attached to the head of a chip mounter, a mirror is usually placed under an electronic component to reflect its image to a camera, so that the angular orientation of the electronic component can be recognized and, if necessary, subsequently corrected.
FIG. 1 is a schematic view of the conventional head-attached component recognition apparatus. As shown in FIG. 1, the conventional component recognition apparatus includes a nozzle 11, a mirror 12, a camera 13, and a driving mechanism 14. The nozzle 11, mirror 12, camera 13, and driving mechanism 14 are all installed on a head (not shown) of a chip mounter. The mirror 12 is arranged directly under an electronic component P that is held by the nozzle 11.
An image of the electronic component P is reflected by the mirror 12 and input to the camera 13 along an optical axis. In this case, the mirror 12 is configured to rotate clockwise to avoid interference with the electronic component P when the nozzle 11 moves downward to pick up and mount the electronic component P. For this purpose, the driving mechanism 14 is installed in the head, which increases the weight of the head.
The increased weight of the head causes higher momentum when the head moves, and thus reduces the component mounting speed. Also, the position and angle of the mirror 12 need to be set accurately by the driving mechanism 14, otherwise the electronic component P to be mounted can be incorrectly recognized.